The present invention relates to an air bag system, to an interior vehicle covering, to a seat, and to a triggering process for an air bag system.
Normally, air bag systems are accommodated behind a covering, such as a dashboard support covering, a door covering, or a seat cover, which tears open when the air bag system is triggered in order to allow an air bag of the air bag system to pass through. For ensuring the safety function of the air bag system, the covering can not significantly hinder the air bag from emerging. Currently, only the force of the inflating air bag is used in practice to rip open the covering along a weakening line, such as a tearing seam or a tearing thread. The strength of the tearing seam, the quality and yield of the material with a high tolerance, and time delay therefore currently affect inflation of an air bag accommodated in such a manner, such as a thorax air bag, out of a seat backrest. Such weakening lines, however, cannot be constructed to be arbitrarily weak, since it is necessary to prevent the covering, such as a seat cover, from opening up there during normal use according to its purpose. Considerable portions of the force of the inflating air bag and the time must therefore be used for opening the covering; this counteracts the provision of the protective function.
Thorax air bags protecting against lateral impacts, for example, are frequently accommodated in seat backrests in the vehicle under covering fabrics in an invisible manner. In order to emerge in the event of a crash, such an air bag destroys the sewn seam at the edge of the seat. A correspondingly high force is required for this purpose. If the seat covers have a low stretching capacity (such as linen), then the air bag still inflates fast in comparison to stretchable coverings, but when considered in an absolute sense, nevertheless with a considerable time delay. With a stretchable covering (such as stretch fabrics or a velour fabric), the air bag first inflates the covering and, in this process, additionally loses force. Time delays of 50% are conceivable. In order to prevent this, "collars" made of a material with a low stretching capacity are sometimes placed around the air bag module and sewn into the seams of the seat cover. High expenditures and a still increased opening force of the seam are required.